JPH03162100A - Microphone equipment and video integration camera mounted with the microphone equipment - Google Patents

Abstract

PURPOSE:To reduce noise near a microphone unit, vibration and wind noise and to attain sound collection with excellent S/N by using a nondirective microphone and unidirectional microphone. CONSTITUTION:An output signal of a unidirectional microphone unit 13 is given to a high pass filter 15 to correct the sudden increase in the sensitivity at a low frequency band due to proximity effect. Moreover, a high pass filter 14 is used to match the frequency characteristic of the output signal of the nondirective microphone unit 12 at a low frequency band with the frequency characteristic of the signal passing through the high pass filter 15. Then outputs of the high pass filters 14, 15 are subtracted together to obtain an output of the microphone unit. Thus, noise near the microphone unit and wind noise are reduced and the sound collection with excellent S/N is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a microphone device that reduces noise, vibration, and wind noise in the vicinity of a microphone unit, and a video camera in which the microphone is housed in the main body. ．． Background of the Invention In recent years, integrated video cameras have become increasingly popular as devices that can easily record audio and video. Along with this, the functions of integrated video cameras have been expanded, and efforts have been made to make them smaller and lighter. Typical examples of conventional video integrated cameras will be explained below with reference to the drawings. FIG. 11 shows the external appearance of a conventional video integrated camera. 111 is a microphone section, 112 is a main body section, 113 is a lens section, and 114 is a viewfinder. In order to avoid the effects of noise and vibration generated by the main body part 112, the microphone part 111 is fixed to the unit through a vibration-proofing material such as rubber, and is installed at a position away from the main body part 112. Furthermore, a windshield is installed to reduce wind noise. Problems to be Solved by the Invention However, when the video integrated camera is further miniaturized, the configuration of the video integrated camera as described above poses problems in terms of both practicality and design. On the other hand, if a microphone unit is embedded in the video integrated camera body as shown in FIG. Therefore, the S/N ratio at the time of sound collection decreases, resulting in a problem that the quality of the recorded sound is significantly degraded. Possible solutions to this problem of reduced S/N ratio include using superdirectivity and using signal processing technology to remove noise, but these are difficult due to space constraints and cost. be. For the above reasons, performance. design. A microphone device that was satisfactory in terms of cost had not yet been developed. An object of the present invention is to provide a microphone device that uses an omnidirectional microphone and a unidirectional microphone to reduce noise, vibration, and wind noise in the vicinity of a microphone unit, and can collect sound with a good S/N ratio. Suppose that Means for Solving tlB In order to achieve the above object, the microphone device of the present invention includes an omnidirectional microphone unit and a unidirectional microphone unit of the same polarity, with their main axes facing the video integrated camera body. , both microphone units are arranged in parallel or with the main axes of both units aligned in a straight line, and the output signals of both microphone units are subtracted after passing through a high-pass filter. However, the polarity of the microphone unit is determined by the sign of the output voltage generated when positive sound pressure is applied from the front of the unit. In addition, an omnidirectional microphone unit and a unidirectional microphone unit, which have opposite polarities, are arranged with their main axes facing the video integrated camera body, and both microphone units are parallel or the main axes of both units are aligned in a straight line. The output signals of both microphone units are then processed after passing through a high-pass filter. In addition, the omnidirectional microphone unit and the unidirectional microphone unit have the same polarity.The omnidirectional microphone has its main axis facing away from the video camera body, and the unidirectional microphone has its main axis facing the video camera. Arrange both microphone units in parallel or with their main axes aligned in a straight line facing the camera body, and set the output signals of both microphone units to be subtracted after passing through a high-pass filter. A polar omnidirectional microphone unit and a unidirectional microphone unit are used.The omnidirectional microphone has its main axis facing away from the video camera body, and the unidirectional microphone has its main axis facing the video camera body. The configuration is such that both microphone units are arranged in parallel or so that the raw axes of both units are aligned in a straight line, and the output signals of both microphone units are added after passing through a high-pass filter. In addition, in each of the above configurations, when vibration is applied to the omnidirectional microphone and the unidirectional microphone, the configuration is fixed so that both unidirectional microphones vibrate as one. Effects of the present invention With the above structure, it is possible to reduce noise, vibration, and wind noise in the vicinity of the microphone unit, and it is possible to collect sound with a good S/N ratio. The microphone remounting of the present invention uses one omnidirectional microphone unit and one unidirectional microphone unit as a pair.
If the polarities of both units are the same, the outputs of both units are subtracted, and if the polarities of the units are opposite to each other, the outputs of both units are added to obtain the output of the microphone device.
When a microphone is used close to a point sound source, the wavefront of the sound wave becomes a spherical wave, and the sound pressure gradient becomes larger than when the wavefront becomes a plane wave far from the sound source, which increases sensitivity mainly in the low frequency range. It will be done. Due to this proximity effect,
Unidirectional microphones exhibit directional characteristics close to bidirectional. Therefore, by subtracting the output of a unidirectional microphone with its main sleeve facing the video camera body from the output of an omnidirectional microphone when the polarities of both units are the same, and adding it when the polarities are opposite to each other. ,
For distant sound sources, it has omnidirectional in the low range, and for high frequencies, it has directional characteristics similar to unidirectional, and for close sound sources, it is possible to realize a microphone mounting with low sensitivity in the main axis direction of the unit. can. Further, as described above, the microphone device of the present invention has omnidirectional directivity characteristics in the low frequency range, so it is possible to realize a microphone device that is not easily affected by wind noise. In addition, the main axes of the omnidirectional microphone unit and the unidirectional microphone unit should be oriented in the same direction, and both units should be fixed so that they vibrate as a unit.If the polarities of both units are the same, subtraction is applied, and if the polarities are opposite to each other, subtraction is performed. By adding , the effects of vibrations applied to the microphone unit can also be removed. EXAMPLE Hereinafter, a microphone device according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows the first embodiment of the present invention.
This figure shows the structure of the microphone installation in the embodiment, and in the same figure, 11 is the video integrated camera body,
12 is an omnidirectional microphone unit, 13 is a unidirectional microphone unit, 14.15 is a high-pass filter, and l6 is a subtracter. Figure 2 shows the directional frequency characteristics when the sound source is 1 meter away from the unidirectional microphone, and Figure 3 shows the directional frequency characteristics when the sound source is near the unidirectional microphone. Solid line in Figures 2 and 3. The dashed line and the dashed-dotted line represent the sensitivity in the directions of 0 degrees, 90 degrees, and 180 degrees, respectively, with respect to the main axis of the microphone unit.
By passing the output signal of the unidirectional microphone unit 13 through the high-pass filter l5, the rapid increase in sensitivity in the low frequency range due to the proximity effect shown in FIG. 3 is corrected. Further, in the low frequency range, a high-pass filter 14 is used to match the frequency characteristics of the output signal of the omnidirectional microphone unit 12 to the frequency characteristics of the signal passed through the high-pass filter 15. Subtract the outputs of the high-pass filters 14 and 15 above to obtain the output of the microphone. Figure 4 is from the microphone reinstallation of this example.
Figure 5 shows the directional frequency characteristics when the sound source is located at a distance of m. Fig. 5 shows the directional frequency characteristics when the sound source is located near the microphone device of this embodiment. Figure 4. In the diagram of Figure 5, solid lines,
Broken line. The dash-dotted lines represent the sensitivity at 0 degrees, 90 degrees, and 180 degrees relative to the front of the video integrated camera. As seen in FIG. 5, according to the microphone device of this embodiment, the sensitivity in the principal axis direction of the unidirectional microphone is greatly reduced to a nearby sound source. Therefore, it is possible to reduce the effects of noise emitted by the video camera body. As described above, according to the microphone remounting of this embodiment, it is possible to reduce noise and wind noise in the vicinity of the microphone unit, and it is possible to collect sound with a good S/N ratio. FIG. 6 shows the configuration of a microphone device according to a second embodiment of the present invention. In the figure, 61 is a video integrated camera body, and 64 and 65 are high-pass filters. It is similar to the IjI precept. 62 is an omnidirectional microphone unit, and 63 is a unidirectional microphone unit, but the difference from FIG. 1 is that the polarities of the units 62 and 63 are opposite to each other, and the adder 66
The point is that According to the microphone device of this embodiment, it is possible to reduce noise and wind noise in the vicinity of the microphone unit, and it is possible to collect sound with a good S/N ratio. FIG. 7 shows the layout of the microphone device according to the third embodiment of the present invention, in which 71 is a video integrated camera body, 73 is a unidirectional microphone unit, and 74.75 is a high-pass The filter 76 is an SX device, and the above structure is the same as that shown in FIG. 72 is an omnidirectional microphone, but the difference from Fig. 1 is that
The main axis of the unit 72 is oriented opposite to the video integrated camera body. According to the microphone device of this embodiment,
It is possible to reduce noise and wind noise near the microphone unit, allowing sound collection with a good S/N ratio. Fig. 8 shows the power of the microphone device in the fourth embodiment of the present invention. It is the same as the configuration. 82 is an omnidirectional microphone unit, and 83 is a unidirectional microphone unit, but the difference from FIG. 7 is that the polarities of the unit 82 and unit 83 are opposite to each other, and an adder 86 is provided. According to the microphone device of this embodiment, it is possible to reduce noise and wind noise in the vicinity of the microphone unit, and it is possible to collect sound with a good S/N ratio. FIG. 9 shows the structure of the microphone device in the fifth embodiment. In the figure, 91 is a video integrated camera body, 94.95 is a high-pass filter, and 96 is a subtracter. It is similar to the composition shown in the figure. 92 is an omnidirectional microphone unit, and 93 is a unidirectional microphone unit, but the difference from FIG. 1 is that the main wheels of both units are arranged in a straight line. According to the microphone device of this embodiment, it is possible to reduce noise and wind noise in the vicinity of the microphone unit, and it is possible to collect sound with a good S/N ratio. FIG. 10 shows the configuration of a microphone device according to a sixth embodiment of the present invention. In the figure, 101 is a video integrated camera body, 104 and 105 are high-pass filters, and 106 is a subtracter. The above is the same as the configuration shown in Figure 1. ■02 is an omnidirectional microphone unit, and 103 is a unidirectional microphone unit, but the difference from Fig. 1 is that when vibration is applied to unit 102 and unit 103, both units vibrate as one unit. This is a point fixed with a fixing metal 1121. According to the microphone device of this embodiment, it is possible to reduce vibrations in addition to noise and wind noise in the vicinity of the microphone unit, and it is possible to collect sound with a good S/N ratio. Effects of the Invention As described above, the present invention provides an omnidirectional microphone unit and a unidirectional microphone unit of the same polarity, with the main axes facing the video integrated camera body, and both microphone units being parallel or with the main axes of both units facing the camera body. Since they are arranged in a straight line and the output signals of both microphone units are subtracted after passing through a high-pass filter, it is possible to reduce noise and wind noise in the vicinity of the microphone unit, and the S/N ratio It is possible to achieve good sound pickup. In addition, an omnidirectional microphone unit and a unidirectional microphone unit, which have opposite polarities, can be arranged with their main axes facing the video integrated camera body, with both microphone units parallel to each other, or with the main axes of both units aligned in a straight line. By using a microphone device that adds the output signals of both microphone units after passing through a high-pass filter, it is possible to reduce noise and calm noise in the vicinity of the microphone unit, and to achieve sound collection with a good S/N ratio. Can be done. In addition, an omnidirectional microphone unit and a unidirectional microphone unit of the same polarity are used.The omnidirectional microphone has its main axis facing away from the video camera body, and the unidirectional microphone has its main axis facing the video camera body. By arranging both microphone units in parallel or with the main axes of both units aligned in a straight line, the output signals of both microphone units are subtracted after passing through a high-pass filter. It becomes possible to reduce noise, and S
It is possible to achieve sound collection with a good /N ratio. In addition, the omnidirectional microphone UNINOTO and the unidirectional microphone unit have opposite polarities, and the omnidirectional microphone has its main axis facing away from the video integrated camera body.
A unidirectional microphone has its main axis facing the video camera body, and both microphone units are placed in parallel or so that the main axes of both unidirectional microphones are aligned in a straight line.The output signals of both microphone units are added after passing through a high-pass filter. With this microphone device, it is possible to reduce noise and wind noise in the vicinity of the microphone unit 7}, and it is possible to realize sound collection with a good S/N ratio. In addition, when vibration is applied to the omnidirectional microphone and the unidirectional microphone in each of the above microphone devices, if the microphone device is fixed so that both units vibrate as a unit, and the main axes of both units are in the same direction, It is possible to reduce noise, wind noise, and vibration near the microphone unit, making it possible to collect sound with a good S/N ratio.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the microphone device in the first embodiment of the present invention, and Fig. 2 is a unidirectional microphone.
3 is a directional frequency characteristic diagram when the sound source is located at a distance of 5 is a directional frequency characteristic diagram when the sound source is located at a distance of 1 m, FIG. 5 is a directional frequency characteristic diagram when the sound source is near the microphone device according to the first embodiment of the present invention, and FIG. A configuration diagram of the microphone equipment in the second embodiment, FIG. 7 is a configuration diagram of the microphone device in the third embodiment of the present invention, and FIG. 8 is a configuration diagram of the microphone device in the embodiment of FIG. 4 of the present invention. 9 is a composition diagram of a microphone device according to a fifth embodiment of the present invention, FIG. 10 is a composition diagram of a microphone device according to a sixth embodiment of the present invention, and FIG. External view of video integrated camera. Figure 12 is a diagram showing the external appearance of a conventional video integrated camera with a built-in microphone in the main body. 11, 61, 71, 81, 91, 101... Video integrated camera body, 12, 62, 72, 82, 92
, 102... Omnidirectional microphone unit,
13, 63, 73, 83, 93, 103... Unidirectional microphone unit, 14, 15, 64, 6
5,74,75,84.85,94,95,104,1
05...High pass filter, 16, 76, 96
, 106... Subtractor, 66.86...
Adder.

Claims (7)

[Claims] (1) An omnidirectional microphone unit and a unidirectional microphone unit of the same polarity are arranged in parallel with their main axes facing the video integrated camera body, and the omnidirectional microphone unit and the unidirectional microphone unit are A microphone device characterized in that an output signal is subtracted after passing through a high-pass filter. (2) An omnidirectional microphone unit and a unidirectional microphone unit having different polarities are arranged in parallel with their main axes facing the video integrated camera body, and the omnidirectional microphone unit and the unidirectional microphone unit are arranged in parallel. A microphone device characterized in that the output signals of are added after passing through a high-pass filter. (3) An omnidirectional microphone unit and a unidirectional microphone unit of the same polarity are provided, the omnidirectional microphone has its main axis facing opposite to the video integrated camera body, and the unidirectional microphone has its main axis are arranged in parallel toward the video integrated camera body, and the output signals of the omnidirectional microphone unit and the unidirectional microphone unit are subtracted after passing through a high-pass filter. (4) An omnidirectional microphone unit and a unidirectional microphone unit are provided with mutually different polarities, the omnidirectional microphone has its main axis facing opposite to the video integrated camera body, and the unidirectional microphone has its main axis opposite to the video integrated camera body. A microphone device characterized in that the main axis is arranged parallel to the video integrated camera body, and the output signals of the omnidirectional microphone unit and the unidirectional microphone unit are added after being passed through a high-pass filter. (5) The microphone according to any one of claims (1) to (4), characterized in that the main axes of both the omnidirectional microphone and the unidirectional microphone are arranged in a straight line. Device. (6) Claims (1) to (1) are characterized in that when vibration is applied to the omnidirectional microphone and the unidirectional microphone, both units are fixed so that they vibrate together.
The microphone device according to any one of 5). (7) A video integrated camera equipped with the microphone device according to any one of claims (1) to (5).